gration as well as the migration of children, at least up until age 15. The migration of married women is more difficult to classify. It can be argued that they migrate only because their husbands do, but in reality they are not always so passive in the making of such decisions. However, there is little doubt that the man's work situation is a key determinant in migration, and much of the following discussion will have men mainly in mind.
The reader is forewarned that world coverage of developing countries will be spotty and unsystematic. Scholars have begun to turn their attention to urbanization and internal migration in developing areas only within the last decade or so. But the trickle has now become something of a flood. Since urbanization and internal migration are multifaceted phenomena, they have attracted the attention of many specialists. At present hundreds of articles and books on these subjects are published each year. Since they appear in many languages and often in fugitive publications, it is impossible to review this output systematically.
In any event, the yield bearing on migrant selectivity from these sources has not, at least until recently, been very great. Although there are a number of studies on the subject, they are generally tangential, not well suited to meet the peculiar methodological requirements of migrant-nonmigrant comparisons. Fortunately, work recently completed or now in progress will soon force a modification of this judgment as more and more researchers, through the use of field surveys, are making migration the focus of their investigations.*
Because I am more familiar with the area, my attention will be concentrated on Latin America. I will also report in some detail the research project I have been engaged in, involving Monterrey, Mexico, as a metropolitan community of destination and Cedral, Mexico, as a rural community of origin for migrants to Monterrey.
The Monterrey and Cedral surveys were explicitly designed to investigate various aspects of the migratory process. The questionnaire instrument included a form in which the complete migratory history (any residences of 6 months or more) was obtained along with marital and work histories. Cedral,
*It was the Centre Latinoamerioa dc Detnogralta (CELADE) that took the lead in survey studies of internal migration to large cities in Latin America. The pioneer and excellent study was of Santiago, Chile (7, 8). CELADE is sponsoring a number of surveys of other Latin American cities. Mascisco is making a comparative study of all the cities surveyed by CELADE. Hcndershot of Vanclerbilt is analy/.ing data collected by the University of the Philippines Population Institute of two rural surveys and one of Manila. Spcarc at Brown is completing a study of migrants and nonmigrants in Taiwan.
Recent efforts to review systematically and codify the available evidence on migration are also encouraging. Although these efforts are not mainly concerned with migrant selectivity as such, they enable us to locate this topic within a broader framework. Cornelius (9) has done this for migration and socio-politico assimilation in Latin American cities and Nelson (10) has made a somewhat similar review of developing countries not restricted to Latin America. Alcrs and Appelbaum (11) have done a good job of building a "prepositional inventory" for 20th century Peru, drawing upon some "59